Mammalian (e.g., human) bodies include various lumen, such as arteries, other blood vessels and bodily cavities. The mammalian lumen, such as a coronary artery, sometimes become constricted or blocked, for example, by plaque or a tumor. A constricted passageway may be widened using an angioplasty procedure using a catheter, which includes a balloon carried by a catheter shaft. Additionally, it may be medically desirable to occlude temporarily or permanently a biological lumen to diagnose or treat an ailment. Such an occlusion may also be realized through the use of a catheter.
Unfortunately, the pressure needed to use a balloon to open or occlude a biological lumen may itself cause injury. For example, in the case of arteries, inflated balloons are known to cause dilation of the artery and the resulting injury to the intima can lead to thickening and narrowing of the artery (Wainwright C L, Miller A M, Wadsworth R M. “Inflammation as a key event in the development of neointima following vascular balloon injury,” Clin. Exp. Pharmacol. Physiol. 2001, 28(11), 891-5; and Labropoulos N, Giannoukas A D, Volteas S K, al Kutoubi A. “Complications of the balloon assisted percutaneous transluminal angioplasty,” J. Cardiovasc. Surg. (Torino) 1994, 35(6), 475-89). Consequently, there is a need for improved methods for using catheters to widen or occlude biological passageways without injuring the lumen. The present invention addresses this need and others.